This invention relates to heating and air conditioning systems for motor vehicles, particularly vehicles having a relatively wide passenger compartment.
Large motor vehicles, such as motor homes and other similar recreational vehicles, have been provided with a front driver's seat and a front passenger seat that are separated by the engine cowling. Accordingly, the distance between the two seats may be substantial. Prior heating and air conditioning systems have employed a single control arrangement for both seats, if not the entire vehicle. However, at any given time either the driver or the passenger may be too hot while the other is too cold, particularly if the vehicle is being driven in the early morning or late afternoon when the sun is shining more through the windows on one side of the vehicle. The only recourse typically available to the passenger and driver is separate control of vents from the common ducting. However, this has not provided the most convenient and efficient climate control since the ducting to both sides of the vehicle still receives a volume of blown air and closing the vents on one side of the vehicle affects the air flow at the other side. Thus, vent adjustment can require subsequent corresponding blower adjustment. Some prior systems have included separate structures and control arrangements for the rear passenger area of the vehicle, but again lateral differentiation in the climate control has not been available. Spacial constraints and weight minimization are important factors in vehicle design and have prohibited elaborate constructions of climate control systems found in static structures.
Furthermore, such vehicles are often equipped with extremely large windshield areas. To effectively provide warm air for defrosting the entire windshield in an acceptable period of time, a significantly larger volume and/or velocity of air may on occasion need to be provided than would normally be needed for passenger climate control. That larger volume of air could be achieved by using a larger blower, but in doing so there would be spacial and cost inefficiencies.
Accordingly, it is an object of the present invention to provide an improved heating and air conditioning system for use in motor vehicles. Other objects include the provision of:
1. an efficient and compact ducting system for air flow in a vehicle climate control arrangement, PA1 2. a system which permits independent lateral control of heating and air conditioning in a vehicle, PA1 3. an efficient vehicle windshield defrosting and defogging system that requires minimal space and operating costs, and PA1 4. a vehicle climate control system that permits simultaneous and independent operation of heating and air conditioning functions.
These and other objects of the present invention are achieved by the provision of a heating and air conditioning system for motor vehicles in which a pair of blowers are controlled to supply air independently to separate lateral ducts or in tandem to the windshield ducts. One blower provides either heated or cooled air to the driver's side of the vehicle, and the other blower provides heated or cooled air to the passenger side of the vehicle. The blowers force air through heating and air conditioning coils and into a plenum. Control damper doors in the plenum control distribution of air between the driver and passenger sides of the vehicle. The individually adjusted blowers enable both the driver and passenger to adjust the heating or cooling on their corresponding side of the vehicle. During a window defrost or defog cycle, a single blower motor may be used to force air onto the windshield area of the vehicle, but a second blower motor may also be used to "boost" the quantity and velocity of the air distributed across the windshield such that the entire windshield area is more quickly covered by the defrost or defog air.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description, with reference to the accompanying drawings.